Reusing yeast sediment

[joolbag]

Thanks headmaster! I enjoyed the feedback from the comp and will keep entering my beers. Good tip about ISB comps. I have joined the Facebook group but have yet to make it to a meeting. Perhaps soon.

 

Next year I will have some lagers to enter for sure. Hoppy pales are tough as timing needs to be spot on to have then judged as they are at their prime hopwise, without being too volatile and green.

 

Back on topic, I used a passata jar as it was clean and in the cupboard. Mine are only 710mL! But I tipped about half of the boiled and cooled water from the passata jar onto the yeast cake from my German Pilsner that I bottled tonight. Swirled and left it for about 7mins and poured a pretty thick slurry into the passata jar. I'll be watching closely to see where the yeast settles. I suspect the one jar that I saved will be a good amount to pitch into a future lager. It's about 1/2 the yeast cake. S-23 yeast this one.

[headmaster]

Let me know if you are thinking of heading in to a meeting there, a great bunch of people, held the first Wednesday of each month.

 

Yes the timing is very important for the IPA's and PA's. The IPA I entered was only just carbonated. They loved it but said it could have used more hop aroma, that would have got me a place or a win in the category.

 

Hopping for my IPA was:

Boil Hops

Hop Type (L/P) Grams Minutes AA% AA% Override IBUs

Magnum Pellets, GR P 42 60 14.7 11.5 44.6

Amarillo P 29 20 8.8 8.5 13.8

Cascade P 29 20 7.2 9.3 15.1

 

Flameout/Whirlpool/Hopstand Hops

Hop Type (L/P) Grams Avg Temp Minutes AA% AA% Override +IBUs

Simcoe P 44 95 10 13 13.2 15.1

Amarillo P 29 95 10 8.8 8.5 6.4

Cascade P 29 95 10 7.2 9.3 7.0

 

Dry Hops

Hop Type (L/P) Grams Location Days Temp Method

Amarillo P 30

Cascade P 30

Simcoe P 30

 

 

I dry hopped at 18 to 20c, probably should have done it cooler to avoid the loss of some aromas, have read some breweries reckon about 14c is good. The freshness of my hops may have been a factor. Also the amount, maybe 90g dry is not enough to really get those aromas happening. So next time will dry hop cooler, with more hops and if possible fresher ones.

[DonPolo]

I was wondering what the advantage of using the yeast cake as a starter was.

 

Do you still need to add dry yeast or other yeast as well as the slurry?

[BlackSands]

I was wondering what the advantage of using the yeast cake as a starter was.

 

Do you still need to add dry yeast or other yeast as well as the slurry?

Using slurry (cake) cuts down on lag time. Once pitched you can expect your fermentation to be well under way in less than 12 hours. AND no, you don't need to add dry yeast, so it saves $ as well. There's debate about how many times you can re-use but one packet of yeast can potentially service many brews before you start over. I've re-used yeast as many as 5 times but I know of some that have cycled many more times than that. By way of example, I purchased a packet of Nottingham yeast a coupe of months ago. From that brew I collected some slurry which was then used in a subsequent brew. I did this a couple more times, but on the 4th cycle I actually collected two jars of slurry. That then serviced two more brews.

[DonPolo]

I was wondering what the advantage of using the yeast cake as a starter was.

 

Do you still need to add dry yeast or other yeast as well as the slurry?

Using slurry (cake) cuts down on lag time. Once pitched you can expect your fermentation to be well under way in less than 12 hours. AND no' date=' you don't need to add dry yeast, so it saves $ as well. There's debate about how many times you can re-use but one packet of yeast can potentially service many brews before you start over. I've re-used yeast as many as 5 times but I know of some that have cycled many more times than that. By way of example, I purchased a packet of Nottingham yeast a coupe of months ago. From that brew I collected some slurry which was then used in a subsequent brew. I did this a couple more times, but on the 4th cycle I actually collected two jars of slurry. That then serviced two more brews. [/quote']

 

Ta! Now I'm in the loop!

[Yuz]

Slightly OT, but is the slurry / yeast cake also useful as nutrient? That is, throwing some slurry into the wort boil?

I've a colony of W34/70 that'd be a waste to throw away.

 

Happy brewing :)

[ChristinaS1]

Slightly OT' date=' but is the slurry / yeast cake also useful as nutrient? That is, throwing some slurry into the wort boil?

I've a colony of W34/70 that'd be a waste to throw away.

 

Happy brewing :)[/quote']

 

Yes, it is, but if you are repitching slurry it isn't necessary, and if you are using a new pack of dry yeast it isn't necessary either. It could come in handy though if you are boiling wort for a starter, for a new batch of liquid yeast.

 

Another use for leftover slurry is to use it as nutrient when making cider, ginger beer, mead, or non-grape wines, which can be short on nutrients; boil it in some water for a few minutes. It doesn't matter how old it is, since you are going to boil it anyway. Just smell it first to make sure it smells okay.

 

Boiled slurry can also be added to a stuck ferment (once cooled) to try to get it going again.

 

Cheers,

 

Christina.

 

 

[DonPolo]

Hi Christina’ I’m a bit confused. I would’ve thought that the boiling would kill the yeast. I can see where you say it helps with the nutrient so that used being alive wouldn’t be an issue but how would it restart the brew if the yeast was dead.

 

But I don’t know about these things so my question is totally uninformed.

[Otto Von Blotto]

Killing yeast turns it into ghost cells which act as nutrients for the live cells. In the case of stuck ferments this can help get it going again.

 

If you do intend to use yeast from the yeast cake in the following batch, simply take about 1/3 of it for pitching (you can save the rest in a jar for a later date if you wish too). Pitching the entire yeast cake is far too much yeast if the following batch is of a similar volume and OG; it won't ruin the brew per se, but huge over pitches can lead to a blander beer because the yeast don't have any real need to multiply. Yeast multiplication is a factor in the flavor of the finished beer. It's also not that great for the overall yeast health either.

 

There are exceptions of course, such as if the following batch is significantly larger in volume, OG or both.

 

Cheers

 

Kelsey

[DonPolo]

So some basic questions:

 

1. How long can you keep a jar of yeast cake in the fridge?

2. Am I right that you remove the jar from the fridge to get it up to around the wort temperature before pitching?

3. Would I be right in saying that you need about a cup of cake for a typical 23 litre batch? In my case that would mean I would be using about 125ml for an 11 litre batch.

4. The yeast I used was from a Coopers Draft kit. Any idea what the actual name of the yeast would be?

5. If the answer to question 1. is "only about a week" then I need to use some new yeast. It has been there for about 2 weeks now I reckon. What would be a good substitute yeast and how much to do a half Cooper's Draft kit with 500g of Brew Enhancer 3 in an 11 litre batch?

 

Cheers DC

 

 

 

[Greenyinthewestofsydney]

So some basic questions:

 

1. How long can you keep a jar of yeast cake in the fridge?

 

A long time. I have had yeast in the fridge for 12 months and used it to make starters. If looking to repitch though I would do it within a week.

2. Am I right that you remove the jar from the fridge to get it up to around the wort temperature before pitching?

 

No Need. Pitch cold is fine.

 

3. Would I be right in saying that you need about a cup of cake for a typical 23 litre batch? In my case that would mean I would be using about 125ml for an 11 litre batch.

 

Depends how long its been sitting there. Need a calculator like the attached link http://www.mrmalty.com/calc/repitch.html

4. The yeast I used was from a Coopers Draft kit. Any idea what the actual name of the yeast would be?

 

Mauribrew Ale 514 I'm thinking

 

5. If the answer to question 1. is “only about a week” then I need to use some new yeast. It has been there for about 2 weeks now I reckon. What would be a good substitute yeast and how much to do a half Cooper's Draft kit with 500g of Brew Enhancer 3 in an 11 litre batch?

 

2 weeks would be fine. Just reuse it but use the calculator for any ale batch IMO. Sub yeast would be US-05 and I would just use the whole packet.

Cheers DC

[DonPolo]

1. How long can you keep a jar of yeast cake in the fridge?

 

A long time. I have had yeast in the fridge for 12 months and used it to make starters. If looking to repitch though I would do it within a week.

 

5. If the answer to question 1. is “only about a week” then I need to use some new yeast. It has been there for about 2 weeks now I reckon.

 

2 weeks would be fine. Just reuse it but use the calculator for any ale batch IMO. Sub yeast would be US-05 and I would just use the whole packet.

Cheers DC

 

Thanks Greeny, though I am having a little trouble reconciling the two answers. I think I don't understand what a starter is and what the difference is between that and repitching. It looks like it says it is OK to keep the yeast in the fridge for 12 months but then you say do it within a week. Sorry just my lack of understanding of terminology.

[Greenyinthewestofsydney]

 

Thanks Greeny, though I am having a little trouble reconciling the two answers. I think I don't understand what a starter is and what the difference is between that and repitching. It looks like it says it is OK to keep the yeast in the fridge for 12 months but then you say do it within a week. Sorry just my lack of understanding of terminology.

 

Its ok mate. No problems.

 

A starter is a growth of new yeast from either a packet of dry yeast, vial of liquid yeast or kept slurry. Basically you put the yeast into a solution of malt and water to grow new yeast cells which are 100% viable as they are brand new and healthy.

 

What I meant was that I had made a starter from some kept slurry which was 12 months old. The slurry probably at that stage only had 10% viability by 1 year but that was enough to get a new starter happening. If I was going to repitch slurry without a starter then I would do that within a week as the viability will drop quickly.

[DonPolo]

 

Thanks Greeny' date=' though I am having a little trouble reconciling the two answers. I think I don't understand what a starter is and what the difference is between that and repitching. It looks like it says it is OK to keep the yeast in the fridge for 12 months but then you say do it within a week. Sorry just my lack of understanding of terminology.

 

Its ok mate. No problems.

 

A starter is a growth of new yeast from either a packet of dry yeast, vial of liquid yeast or kept slurry. Basically you put the yeast into a solution of malt and water to grow new yeast cells which are 100% viable as they are brand new and healthy.

 

What I meant was that I had made a starter from some kept slurry which was 12 months old. The slurry probably at that stage only had 10% viability by 1 year but that was enough to get a new starter happening. If I was going to repitch slurry without a starter then I would do that within a week as the viability will drop quickly.[/quote']

 

Thanks Greeny, I expected as much. However you did say that 2 or so weeks in the fridge should be OK. So should I attempt to make a starter from what I have got or should I just pitch a bit more? The spreadsheet said I should pitch around 65ml. I have way more than that so I have a bit of wriggle room. I reckon that by the time I get around to setting up for a new brew it will be around 3 weeks (down the coast at the moment).

 

Do you think I should pitch about 125ml to take into account that the slurry would by now be less viable?

 

Cheers DC

[Greenyinthewestofsydney]

DonPolo,

 

It wouldn't go unviable that quick. If the calculator says 65mls I reckon 90 by the 3 week mark would be plenty to get the job done.

 

Greeny

[DonPolo]

So last night I pitched about 110 ml of the yeast cake directly into the wort straight from the fridge. I had got the wort down to about 22 degrees (thanks Kelsey for the tip about the cold water from the fridge; next time, I'll get more water in the fridge earlier). Actually I have read that the internal temperature of the wort could have been higher but that is what the thermometer on the outside of the FV was reading.

 

I figured 110 ml was part way between the 90 ml that Greeny advised and the 125 ml that Christina says she always uses (i.e. 250 ml or one cup for a 23 l brew).

 

The FV is in the sink with cold tap water and sundry ice to keep it down around the 20-22 mark.

 

This morning there is quite a good Krausen and because it is only a 15l FV there is a little seepage from the lid despite the clips being in place.

 

So is the seepage a problem? It is in the sink so mess is not an issue but I'm a little concerned about the Krausen pushing out of the lid may somehow allow bacteria etc in.

[Otto Von Blotto]

Krausen pushing out won't allow anything in any more than it not pushing out allows anything in. I wouldn't worry about it but probably not a bad idea to give the lid and rim of the fermenter a wipe over with a sanitised cloth once it dies down.

 

As for the viability, it's surprising how long it actually takes to drop. I did some stain testing on samples of yeast last year where I counted the cells through a microscope, and found that even after two months stored in the fridge the viability was still above 85%, contrasting with online calculator predictions that had it much lower. The thing is though, this was yeast harvested from a starter, so the wort was lower OG and contained no hops. I suspect with yeast harvested from a fermenter of actual beer, that the viability would probably drop faster, but by how much I have no idea and I haven't done any testing on this yet. It is on the to do list though.

 

Point being, after two weeks you'll probably still be running at about 90% viability, maybe 85% at the lowest. This is just a guess though. Once I do a proper test on it I'll be more confident.

 

Cheers

 

Kelsey

[DonPolo]

Krausen pushing out won't allow anything in any more than it not pushing out allows anything in. I wouldn't worry about it but probably not a bad idea to give the lid and rim of the fermenter a wipe over with a sanitised cloth once it dies down.

 

As for the viability' date=' it's surprising how long it actually takes to drop. I did some stain testing on samples of yeast last year where I counted the cells through a microscope, and found that even after two months stored in the fridge the viability was still above 85%, contrasting with online calculator predictions that had it much lower. The thing is though, this was yeast harvested from a starter, so the wort was lower OG and contained no hops. I suspect with yeast harvested from a fermenter of actual beer, that the viability would probably drop faster, but by how much I have no idea and I haven't done any testing on this yet. It is on the to do list though.

 

Point being, after two weeks you'll probably still be running at about 90% viability, maybe 85% at the lowest. This is just a guess though. Once I do a proper test on it I'll be more confident.

 

Cheers

 

Kelsey[/quote']

 

Wiped down the outside of the lid and rim with a cloth last night. But doh! forgot about the 'sanitized' bit. Still it WAS on the outside.

 

Must say impressed by the detail of going to the trouble of counting cells under the microscope! We are lucky to have your advice.

[Otto Von Blotto]

I don't think you'll have any problems. It's not like it's touching the beer itself.

 

Yeah I did the yeast stuff after reading some ideas about viability not dropping as quickly as online sources suggest, so I figured I'd see for myself. I should get back into it really, it just became a bit of a pain doing up a slide and counting it every day. Maybe once or twice a week would be better to get an average drop over time.

[Tricky Micky]

Thanks all for your fantastic contributions here. Yeast slurry here I come. What a great thread this is - Thank-you!

[Tricky Micky]

Reading through this thread, have I got this right in thinking that if I've dry hopped my last brew (hop pellets in a chux or similar) that I should not use the yeast cake from this batch for a yeast slurry for the next brew?

[Tricky Micky]

29 minutes ago, Greeny1525229549 said:

Apparently the PC police are out and about and my post has been blocked pending approval.

Thanks Greeny mate, much appreciated - happy days. 

[BlackSands]

I've been reusing a kveik voss slurry now for over 9 months - I have used it for a variety of beers - broken pretty much all the 'rules' (heresay) regarding when and when not to reuse slurry.  Many brews later it's still going strong and consistently producing great beer.  I intend to keep going with it until there's solid evidence that it's no longer a good idea at which time I'll dig deep and buy a fresh packet!

[jamiek86]

@BlackSands I've never re used more than twice as some beers end up with too much hop matter in bottom do yours have this when re pitch?

yesterday was first time I had ever pitched a whole slurry in a lager at 14 degrees and brang it down to 12 degrees over 3 hours. 6 hours after pitching it had 4cm krausen and is going bat shit crazy on 12 degrees 26 hours later. It has yet to get an sulphur smell like my lagers pitched warm and brang down usually do. The little life forms are amazing what they can do.

Edited July 9, 2021 by jamiek86

[BlackSands]

25 minutes ago, jamiek86 said:

I've never re used more than twice as some beers end up with too much hop matter in bottom do yours have this when re pitch?

Well, my question to you is..."too much hop matter"?  How much is too much, and... so what?  My experience is...  it doesn't appear to matter!  

So far I've had absolutely no perceptable (to me) issue with slurry from dark beers pitched into light beers, or with slurry from heavily hopped beers being pitched into a subsequent brew.  I suspect these supposed issues, like so many things in homebrewing are all "theoretical" and heresay but in practice really aren't a problem at all.